It is known, for the exploitation of solar energy, to arrange a multiplicity of solar panels, in particular, for example, photovoltaic panels, areally adjacent to one another in one or in multiple long rows adjacent to and/or also above one another. To ensure optimum solar irradiation, it is important here for the panels or the surface formed from the panels to be aligned toward the sun in such a way that the greatest possible exposure to light is ensured over the greatest possible part of the day. The panels or the panel rows are therefore installed fixedly with the most expedient possible inclination toward the sun (if, for economic reasons, no provision is made for tracking the sun during the course of the day, such as is likewise known).
If the surface on which the panels are to be installed already predefines a corresponding inclination, such as is often the case for example with roofs, the panels are mounted on the predefined surface, in particular on transverse or longitudinal members, in a row adjacent to one another, if appropriate also in multiple rows one above the other. By contrast, if the predefined surface does not predefine a suitable angle with respect to the sun but rather is horizontal, such as in the case of installation on the ground, the panels or the panel surfaces must be erected such that they assume the desired angle with respect to the sun.
In practice, this is achieved by virtue of the holding members on which the one row or the multiple rows of panels arranged areally adjacent to one another are held being mounted on base members, which are arranged orthogonally with respect to said holding members, of corresponding length, which base members in turn are mounted on the ground via in each case one row of relatively short and one row of relatively long posts in such a way that said base members, and with them the panel rows mounted thereon, are inclined with their surface at the desired angle with respect to the sun. In this way, it is possible for example for entire fields to be populated with such single-row or multi-row panel groups.
For the erection of the panels, there are substantially two different types of construction. Firstly, longitudinal members as so-called base members are fastened in each case to the relatively short and relatively long posts. The inclined transverse members are arranged on said base members, to which transverse members the panels are fastened and which transverse members are therefore also referred to in this case as holding members. Secondly, transverse members as base members are fastened to in each case one short and one long post, to which transverse members the longitudinal members are in turn fastened. The panels are fastened to the longitudinal members, such that said longitudinal members are referred to here as holding members.
In order to be able to operate economically despite the multiplicity of posts required in the case of long panel rows or relatively large fields of panels erected in this way, it is possible, for the anchoring of the posts in the ground, to provide for example conventional screw foundations, or the posts themselves may be formed as screw foundations of said type with a corresponding above-ground elongation.
Such erection arrangements have been in use for a long time in a wide variety of embodiments and have been proven to a greater or lesser extent in one or any other form. They have however also—depending on their type of construction—often exhibited very different disadvantages, it being the intention of the present application to overcome these.
For example, many of the known erection arrangements are too complicated, designed to use too much material, and thus simultaneously too heavy and too expensive. Their construction is in particular too complex and awkward for the often difficult conditions in the terrain, for example also in winter and in the case of ice and snow, and has too great a personnel requirement, which likewise entails an undesired increase in expense.
The materials used, such as for example light metals, are also often too expensive. Furthermore, specific problems are often posed in particular by the necessary alignment of the panel rows, which is important not only for aesthetic reasons and thus for the acceptance of such plants by the public but rather also in order to ensure a harmonious dissipation of the occurring forces, which are generated not only by the plant's own weight but in particular also by wind forces and snow loads.
This yields the object of proposing an erection system/foundation system for solar panels which is of the simplest possible construction, which requires as little material as possible, said material at the same time being as cheap as possible, which is as lightweight as possible and which is easy to handle, that is to say in particular to construct, inter alia with the least possible personnel requirement, and which, here, can withstand the occurring loads in as stable a manner as possible.
In order that simple mounting of the holding members of the panel and of the panels in the intended grid is ensured, that the weight of the mounted panel surfaces can be dissipated or transferred as uniformly as possible to the posts, and that the panel rows or surfaces simultaneously have an appealing appearance, that is to say for example run rectilinearly, it is necessary firstly for the base members arranged on the posts to be aligned or capable of being aligned relatively precisely with the desired nominal profile of the panel rows or of the holding members that support said panel rows, that is to say said base members must, in the installed state, be aligned with one another or run as far as possible linearly and simultaneously parallel to one another.
This could be readily ensured if the rows of posts on which the base members are mounted could themselves be reliably introduced into the ground in an aligned manner in such a way as to be aligned in the direction of the longitudinal members. This is however not the case because, in particular during the screwing-in of screw foundations, disturbances repeatedly arise in the screwing-in process, for example owing to rocks which are situated in the way and which deflect the screw foundation penetrating into the ground out of its direction, with the result of an oblique position of the post.
Said oblique position of the posts can be accepted if it runs in the direction of the longitudinal direction of the longitudinal members. This is because the transverse members or the posts can be fixed to any point of the longitudinal members, and the change in height of a post, and thus in the height of the base member mounted thereon in said region, caused by a change in direction of said post is negligibly small.
By contrast, a deflection of the posts in the longitudinal direction of the transverse members owing to the inclination thereof has a very considerable effect on the height position of the respective transverse member, and therefore requires correction.
The posts may be designed differently in cross section. If they are formed as ground screws, that is to say are screwed into the ground, they typically have a circular cross section and an engagement portion, formed for example as a polygon, hexagon or Torx, for a screwing-in tool.
If, for example, as is conventional, the base members are in the form of a downwardly open rectangular profile or else in the form of a downwardly open U-profile, the problem arises as to how as stable as possible a fastening can be realised between the substantially circular post ends remote from the ground and the planar free sides of the base members.
Furthermore, bores in the post for the purpose of fastening the latter to the base member, for example for a fastening by means of stud bolts, are rejected because the final radial position of the screwed-in posts cannot be predicted, and thus the alignment of corresponding bores with corresponding bores in the base member cannot be ensured in the case of the screwed-in posts.
This gives rise to the object of creating a simple, stable and inexpensive connection between post and base member, which eliminates the stated difficulties.